Control for sheet rolling mills



24; 1935. H, E, BALSIGER "2,025,562

CONTROL FOR SHEET ROLLING MILLS Filed Jim 24, 1952 5 Sheets-Sheet 1 Dec.24, 1935. BALslGER I 2,025,562

CONTROL FOR SHEET ROLLING MILLS Filed June 24, 1932 5 Sheets-Sheet 2 QPM T INVENTO W ATTO NEY Dec. 24, 1935. E. BALSIGER 2,025,562

CONTROL FOR SHEET ROLLING MILLS v Filed June 24, 1952 C 5 Sheets-Sheet 5ATTORNEY Dec. 24, 1935. H. E. BALSIGER 2,025,562

CONTROL FOR SHEET ROLLING MILLS Filed June 24, 1952 5 Sheets-Sheet 4/fl5 m2 urn k N M m x K INVENTOR MCM Dec. 24, 1935. B E 2,025,562

CONTROL FOR SHEET ROLLING M ILLS Filed June 24, 1932 5 Sheets-Sheet 5 IJ 1 J l 1 d l /56 H 5/ Q 1 1 me if 5 505 5x5 E INVENTOR L '-FEI4',BYWFYqwawo w Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE CONTROL FORSHEET ROLLING IWILLS Application June 24, 1932, Serial No. 619,156

8 Claims.

Due to variations in the materials being operated on, the temperatureand also for other reasons the thickness of the product coming from therolls varies widely for any given setting of the roll. The purpose ofthe present invention is to provide an automatic control which isresponsive to'variation in the thickness of the strip to keep thethickness within predetermined limits. The object of the inventiontherefore is to provide automatic mechanically operated mechanism forcontrolling the rolls of a machine which is operating upon material torender it into sheet form.

Other objects and advantages will become apparent from the descriptionwhich follows:

Referring to the accompanying drawings which are made a part hereof andon which similar reference characters indicate similar parts,

Figure 1 is a front elevation of a portion of a rolling mill showing myinvention adapted to the rolls,

Figure 2, a section on line 2-2 of Figure 3, and

Figure 3, a plan view of Figure 2, both figures showing means forkeeping a sizing device in contact with the work,

Figure 4 is a section on line 4-4 of Figure 5, and

Figure 5, a section on line 5-5 of Figure 4, both of these figuresshowing in detail means for adjusting the rolls relative to each other,

Figure 6 is a detail view showing means for operating mechanism formoving the rolls relative to each other,

Figure 7, a section of a cushioning device taken on line 'I 'l of Figure6, and

Figure 8, a diagrammatic view of the control circuits forming a part ofthe invention,

Figure 9 is a modified form showing hydraulic means for adjusting therolls,

Figure 10 is still a further modified form showing a. continuouslyoperating motor with a clutch for changing the direction of operation ofthe rolls and for initiating operation of the direction changing means,

Figure 11 is a diagrammatic showing of a further modified form in whicha reversible motor is used for operating roll adjusting means,

Figure 12 is a detail view of a modified form of roll adjusting screw,and

Figures 13 and 14 are horizontal sectional views of a modified form inwhich the reversible motor shown diagrammatically in Figure 11 is usedfor adjusting the rolls relatively to each other.

In the drawings numeral Ill indicates mill rolls of a type used forforming rubber into sheets of any suitable sort which are mounted insupports I I and are adjustable toward and from each other by means ofshafts I2. Obviously applicants device may be applied to the adjustmentof mills which form other materials into sheets. These shafts are screwthreaded on their upper ends 10 and have mounted thereon worm wheels l3,the rotation of which worm wheels will adjust the shafts vertically. Theworm wheels are mounted in suitable ball bearings I l upon the supportsII. Shafts I5 and I6 provide means for rotating the worm wheel I3. Theshaft I8 is provided with a worm H which engages the Worm wheel I3 andthis shaft is manually operable by means of a hand wheel I8. The shaftI5 is provided with Worm teeth I9 engageable with corresponding 20 teethon the worm I3 and the shaft I5 is mechanically operated by mechanismwhich will be later described. Shafts I5 and I6 are provided withinterengaging beveled gears 20 and 2| so that each shaft is driven bythe other. Secured in the hub of the worm wheel I3 is a short stub shaft22 which carries a head 23. The hub portion 24 of the head 23 may becalibrated as shown at 25 to indicate the vertical position of the shaftl2. The outer end of the shaft I5 carries a toothed wheel 26 by means ofwhich the shaft I5 is rotated. On the outer end of the shaft I5 also isloosely mounted a T-shaped arm 2'7 which is biased to a balancedposition by means of springs 28 and 29 under the opposite arms so 5 thatthe arms will be held normally in a given position. On the third arm ofthe T there is pivoted a ratchet 30 which has two dog portions El and 32engageable with the teeth of the gear wheel 26. The upper end of theratchet 3c is 40 pivoted at 33 to a link 34 which link is attached ateach end to core plungers 35 and 33 of solenoids 31 and 38.

The core 35 is attached to a piston rod 39 to which is secured a piston40 movable in a cylinder 4| The chambers on opposite sides of the pistonM are connected by a fluid passage 42 in which passage is a needle valve43. The valve 43 regulates the flow of fluid from one side of the pistonAll to the other and hence cushions movement of the solenoid core. Thesolenoids are energized by circuits which will now be described.

A nozzle 44 is positioned adjacent the surface of the strip t5 whichstrip is being formed between the rolls. A line 45 is connected withsome source of pressure fluid of a constant pressure. Fluid from theline 46 flows through a restriction 41 into a pipe 48 from which latterpipe it issues through the nozzle 44 escaping between the end of thenozzle and the surface of the work on strip 45. Due to the Velocity ofthe fluid, issuing through the restriction at 41 there will be an areaof reduced pressure in the pipe 49 and in the chamber 50 in one leg of aU-tube This reduced pressure is the result of the Venturi action of thejet of fluid at 41. The U-tube 5| will be partially filled with someliquid such as mercury 52. One leg of the U-tube will contain a contactelement 53 which is connected to a wire 54. 'Within the other leg of theU-tube are positioned contact elements 55 and 56. The element 55 iswithin the body of mercury while the contact element 56 is normallyabove the mercury. Element 56 is connected by wire 5'I'to a post 58carof convenience in describing the invention we will assume that wiresBI and 62 are direct current lines. This current is at high potentialand must be reduced either by a transformer or a resistance. 63, 64' and65 designate a series of resistors so that between point 66 and point.61 there is a total voltage drop substantially equal to the linevoltage. Assume that contacts 55 and 56 have been closed by the mercuryin the left leg of the -U-tube the circuit then will be closed fromcontact 56 through wires 51, 68, coil 69,

wire 10, point 61 andthrough wire H to wire 6|. From contact point 55the circuit is closed through wire 12 through switch 13, wire I4 throughresistance 65,- resistance 63, point 66 and wire 15 to connect with linewire'62. This energizes the coil 69 and. closes the switch 16. When theswitch 16 is closed the circuit is closed with lead-in lines 6| and 62through wires 11, 18 and 19. This energizes the solenoid 38 and movesthe ratchet 30 to the left to rotate the wheel 26 counterclockwise asshown in Figure 6. The'circuit through the line 12 and 14 can only beclosed when the switch at 73 is closed. This switch will be closedo-nly'for a short time and that is when a cam 86 engages an element 8| 7on the'switch to lift the switch to closed position.

The cam 86 is on a wheel or disk 82 which is rotated at a constant speedand continuously, and switch 13 therefore is continuously opened andclosed. If contacts 56 and 55 are closed at the 7 'same time. then thecircuits will be set up as indicated and the solenoid 38 will beenergized.

The energizing will be intermittent so that the core of the solenoidwill be reciprocated to rock the wheel 26 toward the left. The parts areso arranged that it will be apparent from the drawings that contacts 55and 56 will only be closed when there is suflicient pressure in thechamber 5!) to raise the column of mercury in the left leg ofthe U-tube.The device will be set so that 'fluid may issue from the nozzle 44 at agiven rate and so that contacts 56 and 53 will be out of the body ofmercury. If the material 45 should become thicker so that the spacebetween the sure in the pipe 49 and in the chamber 58.

nozzle and the surface of the work decreases then fluid cannot escape asfreely. This will cause pressure to build up in the tube 48 and willdecrease the velocity of the fluid issuing through the restrictedpassage at 41. The reduced velocity at 41 will decrease the aspiratingeffect of the fluid in pipe 49 and hence increase the. pressure in thechamber 50 to move the column of mercury in the left leg of the tubeupward until it closes contact between points 55 and 55. When thisoccurs the material being formed is too thick. The solenoid 38 isenergized at this time to rock the wheel 26 counterclockwise. The wheel26 in turn will rotate the worm wheel I3 to move the shaft so as tobring the working rolls closer together. If the solenoid 38 werecontinuously energized there would be no racking of the wheel 26. It isnecessary to have the circuit continuously interrupting in order toprovide this racking. The cam 80 provides for intermittently 2-0breaking and closing contacts which interrupt the circuit. 4 a

Contact 53 is connected through wire 54 through coil 83.

When the sheet of material 45 becomes thinner than the predeterminedamount the space between the end of the nozzle 44 and the surface of thework becomes wider so that air may issue faster from the pipe 48. Thisincreases the velocity of the air through the restricted line 41 and theaspirating effect of the air reduces the pres- The column of mercuryarises in the right leg of the U-tube and makes contact between points53 and 55. A circuit then is closed through line 54, coil 83, line 84,binding post 85, resistance 63 and point 66 to connect with wire 15 andto lead-in wire 62. The circuit is closed from point 55 through wire 12,switch I3, wire 14, resistance 64 and wire H which connects the lead-inwire 6 I. This circuit energizes coil 83 and closes switch 86. When 86is closed the circuit will be closed from lead-in wires 6| and 62through wires 11 and 18, switch 86 and wires 8'! and 88 to energizesolenoid 31. This actuates the plunger 35 to move it to the right asshown in Figure 6 to operate the gear wheel 26 in a clockwise direction.Of course the cam 80 will intermittently make and break the switch 13 sothat the solenoid will be operated intermittently. When the gear wheel26 is rotated clockwise worm gear 13 will be rotated so as to raise theshaft l2 and to move the rolls away from each other to increase thethickness of the sheet of material which is being formed between therolls.

The second U-tube shown in Figure 8 is a dupli- .cate of that justdescribed. It is advisable to have moved independently of the other byits own siz- 603 ing device and control mechanism associated therewith.The circuits are identical with those just described. It is thereforethought unnecessary to repeat the description. At 89 are showncondensers which are provided to prevent sparking between the contactpoints 56 and 53 and the surface of the body of mercury. The circuitthrough the condensers'is closed through line 68, condenser 89, line 90,resistance 9|, line 14 and line This reduces arcing across contactpoints. Four such condensers are shown in circuit with each of thesolenoids. The condensers all operate in the same manner so it isthought unnecessary to describe more than one.

In order to determine the thickness of the material being formed a plate92 (Fig. 2) is provided which rests against the periphery of the roll asshown'a't 93. This plate is carried on a block 94 which is adjustablysupported on an arm 95. The nozzle 44 is adjustably mounted in the block94 and may be moved toward and from the surface of the work by anadjustable nut 96. The space between the surface of the work and the endof the nozzle will at all times be just slightly in excess of thedesired thickness of the work. i The arm 94 is one arm of a rock armwhich is pivoted at 91 to some stationary portion of the machine.Weights 98 are suspended from the other arm 99 of the rock arm and theseweights maintain the plate 92 in contact with a surface of the roll.

In the modified form of construction shown in Figure 9 a piston I00 iscarried in a cylinder IOI and is operated by fluid from lines I02 andI03. A lever I04 which corresponds to lever 30 in Figure 6 engages anotch in the piston I00 so that the lever is rocked upon operation ofthe piston. Springs I05 and I06 hold the lever in central position whenpressure fluid is released from lines I02 and I03. When in the positionshown in Figure 9 lines I02 and I03 are open to exhaust lines I01through which lines pressure .fluidmay exhaust to a reservoir I08. Whenvalves I09 are shifting either to the right or to the left by solenoidsI I0, I I I, pressure fluid line 'I I2 is put in communication with lineI03 or I02 depending on whether solenoid H0 or III is energized.Solenoids IIO, III correspond to solenoids 83 and 69 shown in Figure 8,which solenoids are energized when contact is made between points 53 and55 or 56 and 55 respectively.

In Figure 10 there is provided a continuously operating electric motor II3 which drives the bevel gear I'I4 through speed reducing gears I15,H6, I I1, I I8. Bevel gear I I4 meshes with corresponding bevel gears H9and I20 which latter bevel gears are loosely mounted upon the shaft I2Iwhich carries a Worm gear I22 by means of which the roll adjusting shaftis operated. Clutch elements I23 are keyed to the shaft I2I and areshifted into engagement with beveled gears II9 and I20 by a lever I24.The lever is held in neutral position normally between springs I25. Whensolenoid I25 is energized the lever I24 is rocked clockwise to bring theclutch I23 into engagement with the clutch I20 so that the shaft I2I maybe rotated. When solenoid I21 is energized the clutch will be broughtinto engagement with beveled gear I I9 to rotate theshaft I2I in thereverse direction. The rollstherefore will be adjusted toward each otheror from each other in accordance with whether solenoid I26 or I21 isenergized. The contact points in the mercury tube will determine whichof solenoids I26 or I21 is energized. When material of the correctthickness is passing between the rolls as determined by the sizingdevice at 44 in Figure 8 neither of the solenoids will be energized sothat the lever I24 will be maintained in the neutral position by springsI25. When the thickness of the sheet varies beyond a predeterminedlimit, either one or the other solenoids will be energized to shift therolls to bring the sheet back to the desired thickness.

In Figure 11 a reversible motor I21 is provided which is controlled byswitches I28, I29, I30, I3I. Lines I32 and I33 correspond respectivelyto lines 68 and 54 in Figure 8.

When the circuit is closed across lines I32 and I33 solenoid I34 isenergized to close switches I28 and I29. This will close the circuitthrough power line I35, switch I29, through line I36, motor I21, lineI31, switch I29, line I38 to lead-in line I39. This will operate themotor I21 in one direction. When the circuit is closed. across lines I40and MI solenoid I42 will be energized to close switches I30--I3I and toopen switches I28 and I29. The circuit will be closed from line I35through switch I30, line I31, motor I21, line I36, line I43, switch I3I,line I38 to power line I39. When in this position it will be apparentthat the terminals of the motor I21 are connected opposite to the way inwhich they are connected when switches I28 and I29 are closed. The motorI21 therefore will be rotated in the opposite direction in a mannerwhich is well known. Dynamic braking is provided in the motor bycontactor I56 closing circuit between contacts I54 and I55. ContactorI56 is carried on. interlocking bar I58 and so proportioned thatcontactor I56 is opened before either the forward or reverse contactorsclose. The motor I21 controls adjustment of the rolls through which thesheet of material is passing. When the thickness of the sheet variesbeyond predetermined limits the position of the rolls is adjusted byrotating motor I21 in one direction or the other depending on whetherthe sheet is too thick or too thin. The motor I21 may be connected foradjusting the rolls in the manner shown in Figures 13 and 14 in whichthe motor operated through a shaft I44, i

a worm I45 which meshes with a worm wheel I46. Worm wheel I46 is on ashaft I41 and carries a worm I48 which meshes with a worm wheel I49. Theworm wheel I49 in turn is mounted on a shaft I50 which carries a wormmeshing with a worm wheel I5I which latter wheel is on a shaft whichadjusts the working rolls relative to each "other. The worm driveconnection just described provides aspeed'reduction between the motorI21 and. the shaft which is connected to the rolls which are to beadjusted.

In the form shown in Figure 12 a spring I52 is provided to insure ayielding element to permit the rolls to separate slightly when objectsbeyond a predetermined thickness are ,carried between the rolls. Theshaft I53 may be rotated in any of the manners described above. For moredetailed description of some features of the device reference may be hadto my copending application Ser. No. 598,498, filed March 12, 1932.

It will be obvious to those skilled in the art that various changes maybe made in my device without departing from the spirit of the inventionand therefore I do not limit myself to what is shown in the drawings anddescribed in the specification, but only as indicated by the appendedclaims. 7

Having thus fully described my said invention, what I claim as new anddesire to secure by Letters Patent, is:

1. In a machine for forming material into sheet form having a pluralityof-rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, and a control means for said adjustingmeans including a nozzle having a fixed position relative to the sheet,a fluid supply line connected-to said nozzle where by fluid isdischarged against the sheet, means associated with said nozzle andresponsive to variations in pressure in the fluid for causingsaicladjusting means to separate the rolls when the sheet decreases below apredetermined desired thickness and to move the rolls toward each otherwhen said sheet increases above the said desired thickness.

2. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, and an electrically actuated controlmeans for said adjusting means including a nozzle having a fixedposition relative to the sheet, a fluid supply line connected to saidnozzle whereby fluid is discharged against the sheet, means associatedwith said nozzle and responsive to variations in pressure in the fluidfor controlling circuits of said control means for causing saidadjusting means to separate the rolls when the sheet decreases below apredetermined desired thickness and for controlling other circuits ofsaid control means for causing the rolls to move toward each other whensaid sheet increases above said desired thickness.

3. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, and an electrically actuated controlmeans for said adjusting means including a nozzle having a fixedposition relative to the sheet, a fluid supply line connected to saidnozzle whereby fluid is discharged against the sheet, means associatedwith said nozzle and responsive to variations in pressure in the fluidfor controlling circuits of said control'means for causing saidadjusting means to separate the rolls when the sheet decreases below apredetermined desired thickness and for controlling circuits of saidcontrol means for causing the rolls to move toward each other when saidsheet increases above said desired thickness, and an intermittentlyoperated control switch in said circuits of the control means wherebysaid adjusting means is operated to intermittently move the roll duringthe adjusting of the same. V

4. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, and an electrically actuated controlmeans for said adjusting means including a nozzle having a fixedposition relative to the sheet, a fluid supply line connected to saidnozzle whereby fluid is discharged against the sheet, said electrically,controlled means including independent circuits operating respectivelyto cause said adjusting means to move the rolls toward each other orfrom each other, means associated with said nozzle and responsive tovariations in pressure in the fluid for controlling the respectivecircuit for moving the rolls toward each other when the sheet increasesabove a predetermined desired thickness and for controlling the otherrespective circuit for moving said rolls away from each other when saidsheet decreases below the predetermined desired thickness. r a

5. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, including a shaft, a pawl and ratchetmechanism for rotating said shaft in one direction or theother, meansfor actuating said pawl, means operating when moved 1 in'one directionfor causing said pawl to operate through said adjusting means toseparate the rollsandwhen moved in the other direction opcrating throughsaid pawl to cause said rolls to operate through said adjusting means tomove tion when said sheet decreases from the desired thickness.

6. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, including a shaft,

a pawl and ratchet mechanism for rotating said shaft in one direction orthe other, means for actuating said pawl, a cylinder, a piston movablein said cylinder and connected to said pawl for moving it in onedirection or the other, a fluid pressure means connected withtheiopposite ends of said cylinder, a valve for controlling the fluidpressure means, whereby fluid under pressure is selectively admitted tothe opposite ends of said cylinder, and a control means for shiftingsaid valve including a nozzle having a fixed position relative to thesheet, a fluid supply line connected to the nozzle whereby fluid isdischarged against the sheet, and means associated withthe nozzle andresponsive to variations in pressure in the fluid for causing said valveto shift in one direction when the sheet decreases below a predetermineddesired thickness and to shift in the other direction when said sheetincreases above the desired thickness.

7. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, including a shaft, a pawl and ratchetmechanism for rotating said shaft in one direction or the other, meansfor actuating said pawl, a cylinder, a piston movable in said cylinderand connected to said pawl for moving it in one direction or the other,a fluid pressure means connected with the opposite ends in pressure inthe fluid for establishing a circuit 7 and causing the valve to shift inone direction upon an increase in thickness of the sheet above apredetermined thickness and for establishing a a circuit to cause saidvalve to shift in the other direction when said sheet decreases belowthe predetermined desired thickness. V

8. In a machine for forming material into sheet form having a pluralityof rolls, means for adjusting the rolls toward and from each other tovary the thickness of the sheet, including a shaft, a pawl and ratchetmechanism for rotate ing said shaft in one direction or the other, meansfor actuating said pawl, a cylinder, a piston movable in said cylinderand connected to said pawl for moving, it in one direction or the other,a

fluid pressure means connected with the opposite ends of saidcylinder,'a valve for controlling the fluid pressure means wherebypressure fluid is selectively admitted to the opposite ends of saidcylinder, an electrically actuated control means for shifting said valveincluding a nozzle having a fixed position relative to the sheet, afluid supply line connected to said nozzle whereby fluid is dischargedagainst the sheet, and means associated with the nozzle and responsiveto variations in pressure in the fluid for establishing a circuit andcausing the valve to shift in one direction upon an increase inthickness of the 10 sheet above a predetermined thickness and for

